torus tubarius

例句：

1. 1. The torus is a spherical object that has a hole in the middle.
   这个环状物体有一个中间的洞。
2. 2. The torus is used as a support for the roof of a building.
   这个环状物体用作建筑物屋顶的支撑。
3. 3. The torus is a shape that resembles a doughnut.
   这个形状类似于甜甜圈。